Shank cutters are provided with finer teeth than ordinary cutters, the following being the numbers of teeth commonly employed for the respective diameters:—
| Diameter | of cutter | 1⁄8 or 3⁄16 | inch, | number | of teeth | 6 |
| „ | „ | 1⁄4 | „ | „ | „ | 7 |
| „ | „ | 3⁄8 | „ | „ | „ | 8 |
| „ | „ | 1⁄2 | „ | „ | „ | 8 |
| „ | „ | 5⁄8 | „ | „ | „ | 10 |
| „ | „ | 3⁄4 | „ | „ | „ | 10 |
| „ | „ | 7⁄8 | „ | „ | „ | 12 |
| „ | „ | 1 | „ | „ | „ | 14 |
The front faces of the teeth are radial as in other cutters, the angle of the back of the tooth being 40° for the smaller, 50° for the medium, and 60° for an inch cutter.
Fly cutters are single-toothed cutters, or rather tools, that are largely used by watchmakers for cutting their fine pitches of gear wheels.
Fig. 1938.
[Fig. 1938] represents a fly cutter in place in its holder or arbor, its front face d being in line with the axis c of the arbor.
